The epididymis is an important part of the male reproductive system. It is a single, narrow, tightly-coiled tube (in adult humans, six to seven meters in length) connecting the efferent ducts from the rear of each testicle to its vas deferens.

Percutaneous Epididymal Sperm Aspiration (PESA) is a technique for retrieving sperm from the epididymis. The advantages of this technique are that it can be performed without surgically exploring the scrotum, it can be repeated easily and at low cost, and it does not require an operating microscope or expertise in microsurgery. The procedure is usually performed under local or general anesthesia.

Procedure:

After induction of anesthesia, the testis is stabilised and the epididymis is held between the surgeon′s thumb and forefinger.

A 21-gauge butterfly needle attached to a 20 ml syringe is inserted into the caput epididymis and withdrawn gently until fluid can be seen entering the tubing of the aspiration set.

The tubing is clamped, the 20 ml syringe removed, and the tubing is back flushed with medium. The procedure is repeated until adequate amounts of epididymal fluid with motile sperm are retrieved. If no sperm are retrieved, as occurs in at least 20% of sperm retrieval attempts, then it is necessary to proceed with MESA, testis biopsy or testicular aspiration.